The attack at a Colorado Planned Parenthood clinic that killed a police officer and two other people suggests that both sides of the abortion debate in the United States need to "tone down the rhetoric," the state's governor said on Sunday.

The governor, John Hickenlooper, spoke the morning after unnamed law enforcement authorities told NBC News and other media that the suspected gunman had muttered "no more baby parts" when he was arrested after an hours-long standoff at the Colorado Springs clinic.

Planned Parenthood provides a range of health services for men and women, including abortion.

The remark attributed to 57-year-old Robert Lewis Dear appeared to be a reference to Planned Parenthood's abortion activities and its role in delivering fetal tissue to researchers, a hot button issue in the 2016 race for the presidency.

COLORADO SPRINGS, CO - NOVEMBER 27: A suspect is led away in handcuffs by police during an active shooter situation outside a Planned Parenthood facility where an active shooter reportedly injured up to eleven people, including at least five police officers, on November 27, 2015 in Colorado Springs, Colorado. Police continue to investigate the scene and are searching the buiding for possible explosive devices. (Photo by Justin Edmonds/Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: A suspect is led away in handcuffs by police during an active shooter situation outside a Planned Parenthood facility where an active shooter reportedly injured up to eleven people, including at least five police officers, on November 27, 2015 in Colorado Springs, Colorado. Police continue to investigate the scene and are searching the buiding for possible explosive devices. (Photo by Justin Edmonds/Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: A suspect is led away in handcuffs by police during an active shooter situation outside a Planned Parenthood facility where an active shooter reportedly injured up to eleven people, including at least five police officers, on November 27, 2015 in Colorado Springs, Colorado. Police continue to investigate the scene and are searching the buiding for possible explosive devices. (Photo by Justin Edmonds/Getty Images)

People are escorted away from the scene by police after a gunman opened fire at a Planned Parenthood facility on Centennial Boulevard in Colorado Springs, Colo., on Friday, Nov. 27, 2015. The gunman was captured alive. (Daniel Owen/Colorado Springs Gazette/TNS via Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: An officer waits on the intersection of Windmill and Centennial while facing south towards the scene of a shooting November 27, 2015 in Colorado Springs, CO. (Photo by Brent Lewis/The Denver Post via Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: People are rescued near the scene of a shooting at the Planned Parenthood clinic in Colorado Springs Friday November 27, 2015.(Photo by Andy Cross/The Denver Post via Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: People are rescued near the scene of a shooting at the Planned Parenthood clinic in Colorado Springs Friday November 27, 2015. (Photo by Andy Cross/The Denver Post via Getty Images)

Police respond to the scene with an active shooter near the Planned Parenthood at Fillmore and Centennial in Colorado Springs, Colo., on Friday, Nov. 27, 2015. (Stacie Scott/Colorado Springs Gazette/TNS via Getty Images)

A Colorado Springs police officer is transported from the tactical vehicle to an ambulance after a gunman opened fire at a Planned Parenthood facility on Centennial Boulevard in Colorado Springs, Colo., on Friday, Nov. 27, 2015. The gunman was captured alive. (Daniel Owen/Colorado Springs Gazette/TNS via Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: A member of the Colorado Springs sheriff's department secures the scene during an active shooter situation near a Planned Parenthood facility where an unidentified suspect has reportedly injured up to nine people, including at least four police officers, on November 27, 2015 in Colorado Springs, Colorado. A standoff has developed outside the clinic and the area is on lockdown. (Photo by Justin Edmonds/Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: Colorado Springs Police spokesperson Lt. Catherine Buckley addresses the media during an active shooter situation near a Planned Parenthood facility where an unidentified suspect has reportedly injured up to nine people, including at least four police officers, on November 27, 2015 in Colorado Springs, Colorado. A standoff developed outside the clinic and the area is on lockdown. (Photo by Justin Edmonds/Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: People are rescued near the scene of a shooting in Colorado Springs Friday November 27, 2015. (Photo by Andy Cross/The Denver Post via Getty Images)

COLORADO SPRINGS, CO - NOVEMBER 27: People are rescued near the scene of a shooting at the Planned Parenthood clinic in Colorado Springs Friday November 27, 2015. (Photo by Andy Cross/The Denver Post via Getty Images)

An officer from the Colorado Springs K-9 Unit is being transferred from a tactical vehicle to an ambulance before being transported from the scene during a shooting incident n Colorado Springs, Colo., on Friday, Nov. 27, 2015. (Daniel Owen/Colorado Springs Gazette/TNS via Getty Images)

COLORADO SPRINGS, CO - NOV. 27: Members of law enforcement enter the emergency room at Penrose Hospital in Colorado Springs where some people were transported from an active shooting near a shopping center, where an armed person is insided a Planned Parenthood and has been shooting at police officers outside. (Photo by Kathryn Scott Osler/The Denver Post via Getty Images)

Hickenlooper, a Democrat, told CNN that the shooting and similar acts of mass violence might be a function of the "inflammatory rhetoric we see on all levels," referring to the heated debate over abortion.

"I think we should have a discussion at least urging caution when we discuss some of these issues, so we don't get people to a point of going out and committing violence," he said, describing the rampage as "a form of terrorism."

The shooting on Friday was believed to be the first deadly attack at an abortion provider in the United States in six years. The Colorado Springs center has been repeatedly targeted for protests by anti-abortion activists.

While Dear's reported remarks could hint at a possible motive, the sources told NBC that investigators were still not sure of why the gunman launched the attack in which nine people were also injured.

The reports could not be independently confirmed and authorities have steadfastly declined to discuss a possible motive for the attack, saying their investigation was still underway.

Dear, a South Carolina man who appeared to have moved to Colorado last year, has been jailed ahead of a court appearance scheduled for Monday.

Planned Parenthood, however, suggested that the reports were clear evidence of a motive.

"We now know the man responsible for the tragic shooting at PP's health center in CO was motivated by opposition to safe and legal abortion," the organization said on Twitter.

While calling the shooting "an incredible tragedy," Republican presidential candidate Mike Huckabee on Sunday dismissed talk that harsh anti-abortion rhetoric may have contributed to the attack. But he also drew a direct parallel between the attack and abortion.

"There's no excuse for killing other people, whether it's inside ... Planned Parenthood clinics, where many millions of babies die, or whether it's people attacking Planned Parenthood," the former Arkansas governor told CNN, saying the attack was an act of "domestic terrorism."

Abortion opponents stepped up their criticism of Planned Parenthood this year after officials of the organization were secretly recorded by an anti-abortion group discussing how to obtain human tissue from aborted fetuses. The non-profit organization has strongly denied doing anything illegal or unethical.

TWO CIVILIAN CASUALTIES

Colorado's Hickenlooper also disclosed that the two civilian fatalities were a man and a woman, but he offered no further information and would not say whether they were patients or employees at the clinic. Planned Parenthood said all of its employees escaped unharmed.

Authorities have said they would say nothing about the pair until after their autopsy reports, likely on Monday.

Garrett Swasey, 44, the police officer killed in the attack, worked for the University of Colorado at Colorado Springs. He had joined city police in responding to reports of shots fired at the clinic. The father of two served as an elder at Hope Chapel, the church said on its website.

Except for his name and age, police have said only that Dear recently resided in rural Hartsel, Colorado, about 60 miles (96 km) west of Colorado Springs. Official records show that he has a history of brushes with the law, mostly in South Carolina but no criminal convictions.

At least eight workers at clinics providing abortions have been killed since 1977, according to the National Abortion Federation. The most recent was in 2009 when doctor George Tiller was shot dead at church in Wichita, Kansas.